Continuous filter



Sept. 27, 1932. I R A s 1,878,998

CONTINUOUS. FILTER Filed May 1,1951 5 Sheets-Sheet 1 Sept. 27, 1932. R. P. AKINS 1,878,993

CONTINUOUS FILTER I Filed May 1, 1951 3 Sheets-Sheet 2 I Sept. 27, 1932. R. P. AKINS 1,878,998

CONTINUOUS FILTER Filed May 1, 1931 3 Sheets-Sheet 3 Patented Sept. 27. 1932 4 UNITED STATES-PATENT; OFFICE This invention relates to a continuousfiltering machine, and ject the provision of tinuously remove the filtrate from the pulp; continuously discharge the filter cake; and

continuously provide pulp. Anotherobject of the invention is'to provide a filter in which the pulp for the incomin the top of a revolvin it in individual poc being drawn therefrom.

A further object of the invention is to proremoving excess filtrate which vide means for does not have an opp the filter medium and return'this excess .to

the feed for retreatment.

A still further object of the invention is to so construct the machine that gravity will assist both in the filt tion of the machine cient governor mechanism operation of the machine.

A still further object of the invention is to governor mechanism that it so construct the will allow the drum detail constructi ciency. These will from the invention reference'i mg drawings which form a part numerals In thedrawin the filtering pans. Fig. 3 is a vertical 3-3, Fig. 1.

, i Fig. 4 is a detail face view of the 'bonduit I plate.

Fig. 5 is a detail vi face ofthe valve plate.

following description. In the following detailed description of the refer to like parts in all views of the drawings and throughout the description mam. Rams, or nEiwnn, coromo I commons FILTER Application filed May 1, 1931. Serial No. 534,241.

has

for its principal ob face of the valve plate. filter whichwill congovernor mechanism.

a clean-filter medium in the filter pans.

Fig.9 is a det will be fed at illustrating the drum which will retain ets while the filtrate is ranged to receive tom. the descending side, through the' the cake is dischar pressed air.

ortunity to pass-through ration and in the opera and to provide an eflifor controlling the present continuous the pulp-at the top,

the machine since the to rotate intennittently be entirely empt supporting frame shaft bearing 11 and a become more apparent extremity in the shaft s had to the accompanyv the trunnion bearing hereof. Like rotate with the shaft prises a radial series of the rim the spokes the supports for to the rim plates with a screen sub section taken on the line brought up over: the

Fig. 6 is a detailview Fig. 7 is an end elevation Fig. 8 is a detail view il for use in holding the filter medium in place pockets will contain mo cake, while the upwardly moving pockets will 75 illustrating the outer I illustrating the ail section through a filter pan frame of Fig. 8 in place. Briefly, the invention comprises'a rotating series of outwardly facing pockets or pans arthe pulp or solution at the top and discharge the filter cake at the bot- Between the top r the filtrate is drawn filter medium. At the bottom ed by means of com and the bottom, on i This system has many advantages over the ;filters in that, by feeding gra mg process and also ass vity assists the filterists in the rotation of downwardly moving re 'or less solution and One method of constructing the machine is outlinedon the drawings, in which, a suitable 10 is illustrated carrying a trunnion bearing 12.80- A horizontal shaft 13 rotates adjacent its one bearing 11 and is carried in a trunnion block'14 adjacent its other extremity. The trunnion block 14 rotates in i 12. A pair of wheels 13. Each wheel com spokes 15nsupporting I an annular rim late 16.

series of fi ter pans 17 extend. between plates 16 and between each pairof The pans 17 are. supported on angle seats 18 riveted or'otherwise secured 16. Each pan is provided -bottom las'adapted to sup-" port a filter cloth QO-or'other suitable filter- 9 ing medium. Thefiltering medium maybe edges: of the pans and wedged in'placeby' means of T shaped wedge 21 ndependent conduits 2 2 lead from; each .of no lustrating aframe 55 I the pans 17 into the trunnion upon a clamp bolt 26'secured in the end of the shaft 13. The valve plate 24 is provided with an arcuate vacuum port 27, an air port 28, and a vibrating port 29. A vacuum pipe 30 leads from the vacuum port 27 to any suitable vacuum pump. A compressed air pipe 31 leads to the compressed air port 28 from any suitable air compressor or reservoir. A second air pipe 32'leads from the vibrating port 29.

The machine is fed at the top from any suitable feed hopper 33 and the filter cake is dlscharged at the bottom into a receiving hopper 34. The feed hopper 33is provided with a perforated plate 38 which acts both to distribute the feed over the entire area of the pans and also protects the pump 36, from rocks and other foreign materials. An overflow hopper 35 is positioned on the downwardly moving side of the machine. The hopper 35 communicates with a pump 36 which acts to return any over-flowing pulp through a return pipe 37 to the circuit ahead of the filter. the feed hopper 35, for catching the unfiltered portion of the solution and returning it to the feed circuit is one of the principal features of the invention. This removes all necessity for the constant and minute regulation of the feed usually necessary with continuous filters. An overfeed will in no way interfere with the operation of the filter and will always insure maximum capacity. While the return pipe 37 is illustrated as returning solution to the feed hopper 33 it could, of course, return it to any point in the circuit ahead of the filter.

The machine may be rotated in any desired manner. It is preferred, however, to allow the weight of the solution and cake in the descending pans to rotate the wheel and to provide a governor to control the rotation thereof so that the wheel will pause for an instant as each pan reaches the top so as to allow the pan to be properly filled.

This may be accomplished by means of the governor mechanism illustrated in Fig. 7 1n which, a ratchet wheel 41 is secured to the shaft 13'. The ratchet wheel is provided with a series of notches 42 corresponding in number to the series of pans 17. A tooth 43, formed adjacent one extremity of a gravity lever 44, is arranged to successively enter the notches 42. The other extremity of the lever 44 is hinged at 46.

The tooth 43 is caused to release itself at predetermined intervals by means of a rock- 'ing pan 47. The rocking pan is provided with a relatively high middle partition 48 which divldes it into two compartments one The provision of-means, such as on each side of a rocking shaft 49. A water pipe 50 controlled by a valve terminates above the partition 48 so that the latter will swing from side to side thereof as the rocking pan 47 tilts.

The rocking motion of the pan 47 is communicated to a pendulum arm 51 by means of a crank 52 and a link 53 and the pendulum arm 51, in turn, transmits'this motion to a sliding member 54. One extremity of the sliding member 54 carries a roller 56 which rolls back and forth along the lower edge of the gravity lever 44 as the sliding member 54 reciprocates. A projecting lug 57 is formed on the said lower edge of the gravity lever and, at each reciprocation of the sliding member 54, the roller 56 will ride under this lug and lift the tooth 43 from the notch 42.

Operation The filter wheel or drum is rotated to the left, as indicated by the arrow A, Fig. 1. As each pan reaches the top it is filled with pulp and solution from the feed hopper The weight of this pulp and solution in the pans on the descending side of the drum always tends to rotate the drum in this direction. The drum, however, is prevented from rotating constantly and from attaining an excessive speed by the governor mechanism. For instance, as each pan reaches the top the tooth 43 will enter one of the notches 42 of the ratchet wheel and stop the rotation of the drum. The drum will remain stationary until the water from the pipe will have filled one of the compartments of the rocking pan 47 sufliciently full to overbalance the latter so as to cause it to tilt and discharge into a receiver 58. This tilting action will reciprocate the'slide 54 so as to cause the roller 56 to strike the projection 57 and lift the tooth 43 from its notch 42 in the ratchet wheel 41. As soon as the tooth 43 leaves the notch 42 gravity acts upon the drum and continues to rotate it until the next pan reaches the top at which time the tooth 43 will drop into the next notch 42 (the roller 56 having by this time passed the lug 57) and stop the drum. Thus the drum will rotate in series of intervals, the length of the stops being so regulated, by the valve 45, as to allow each an to receive the desired quantity of pulp and solution before it leaves the top of the wheel. 7

The compartments of the rocking pan 47 will alternately fill with water, tilt, and decant into the receiver 58. The water discharges from the receiver through a drain 59 which is placed sulficiently far above the receiver bottom to leave a bed of water in the receiver atall times to cushion the tilt of the pan 47.

As each panv reaches the top, the vacuum conduit 22 of that pan is in communication with the vacuum port 27 so that the filtrate 0 til each of these conduits pass the lower extremity of the vacuum port 27 at which time the suction will be closed off. Each conduit will then successively ports 28 and 29.

The first cause air pressure to be injected behlnd each of the filter mediums as they reach the bottom oftheir travel. This air will blow' the filter cake from the filter medium and discharge it into the receiving hopper 34. The conduit will then'move over the vibratin port 29. This port\is preferably connected through a. pump or valve to provide a rapidly. alternating or vibrating current of air, that is, first it will blow the filterlicloth or medium filter cloth or medium outwardly and then draw it inwardly in rapid succession so as to vibrate the filter medium and loosen any adhering portions of filter cake. This vibration thoroughly cleans the filter medium so that it will be ready to receive a fresh supply of pulp upon arriving again at the top.

It is possible that some of the pulp or solution may overflow either to the right or left from the'uppermost pan. 7 The solution overflowing to the right Will be caught and retained in the risin pans until they reach the top. That over owing to the left will be caught in the descending pans and will be acted upon by the vacuum. Should the feed be excessive, or shouldjthe wheel be rotating more rapidly the filtrate, a portion of it will remain in the descending pans. This portion will discharge into the overflow hopper as the pans descend-and will be returned to the feed hopper33 by the pump 36.

It will be noted that the pulp is maintained above the filter mediums at all times so that gravity will assist in drawing the filtrate through the medium.

To prevent the filter medium from being .balloned out of the pans by the action of the compressed air, a frame 60, such as illus trated in Figs.,8 and 9- may be employed. The frame is of a size to fit into the bot- .tom of the pans 17 adjacent the walls thereof and may be held in place by means of spring clips pan edges. v

The term drum as used herein designates the complete structure of the wheels and pans.

'le a specific form of the improvement has been described and illustrated herein, it

is desired to be understood that the same may pass'over the two air port is so positioned that it will fl predetermined positlon.

than the conduits 22 can remove 61 arranged to clamp over the be varied, within the scope of the appended claims, without departing from the spirit of the invention.

, Having thus described the invention, what is claimed and desired secured "by Letters Patent is v '1. A continuousfilter comprising: an annular series of outwardly facin receptacles, said series arranged to rotate it out an axis in a vertical plane; a filter medium in said receptacles; means for creating a partial vacuum in said receptacles on the descending side of said series; means for feedingand an overmaterial at the top of said series; ow hopper positioned to one side of said 3X18 and extending beneath-the descending side only of said series so ,as to receive the overflow, if any, from the receptacles at said descending side. V

2. A continuous filter comprising an ang nular series of outwardly facingreceptacles,

said series arrange to rotate about an axis in a vertical plane; a filter med um in said re ceptacles; an indepenedent condu1t from each receptacle; means for creating-a partial vacuum in said conduits on the descending side of said series ;.means for feeding material at the top of said series; and means for stopping the rotation of said series for, an interval as each receptacle reaches a certain 3. A continuous-filter comprising: an annular series of outwardly facing receptacles, said series arranged to rotate about an axis in a vertical plane; a filter medium in said receptacles; an independent conduit from each, receptacle; means for creating a par tial vacuum in said conduits on the descending side of said series; means for feeding material at the top of said series; a notched wheel arranged to rotate with said series; a tooth positioned to engage in the notches of said wheel as each receptacle reaches the feeding means; and means for withdrawing said tooth after a predetermined interval. 4. A continuous filter comprising: an an nular series of outwardly facing receptacles, said series arranged to rotate about an axis in a vertical plane; a filter medium in said receptacles; an independent conduit from each receptacle; means for creating a partial vacuum in said conduits on of said series means for feeding material at the top of said series; a notched wheel ar: ranged to rotate with said series'; a tooth positioned to engage in the notches of said Wheel as each receptacle reaches the feeding means; means for withdrawing said tooth after a predetermined interval, said latter meanscomprisinga two compartment pan; means for alternately filling andemptying the compartments of said pan so as to cause the latter to tilt; and means for transmitting said tilting action to the descending side i said tooth so as'to withdraw the latter from successive notches of said wheel.

5. A continuous filter comprising: an annular series of outwardly facing receptacles, 5 said series arranged to rotate about an axis in a vertical plane; a filter medium in said receptacles; an independent conduit from eachreceptacle means for creating a partial vacuum in said conduits on the descending '1 side of said series; means for feeding material at the top ofsaid series; a notched wheel arranged to rotate with said series; a tooth positioned to engage in the notches of said wheel as each receptacle reaches the feeding means; means for withdrawing said tooth after a predetermined interval, said latter means comprising a two compartment pan; means for alternately filling and emp tying the compartments of said pan so as to cause the latter to tilt; means for transmitting said tilting action to said tooth so as to withdraw the latter from successive notches of said wheel, said latter means comprising a lever carrying said tooth; a projection on said lever; and a sliding member operated in consequence of the tilting of said pan and arranged to engage said-projection so as to cause said lever to lift said tooth.

6. A continuous filter comprising: an an- 3 nular seriesof outwardly facing receptacles adapted to rotate in a vertical plane; a filter medium in each of said receptacles; means for creating a partial vacuum below the filter 7 medium in each of said receptacles during a portion of their rotation; means for feeding material into said receptacles; and means for stopping the rotation of said series for an interval as each receptacle reaches a predetermined position.

, 4o 7. A continuous filter comprising: an annular series of outwardly facing receptacles adapted to rotate in a vertical plane; a filter medium in each of said receptacles; means for creating a partial vacuum in said recep- 5 tacles below said filter medium during a portion of their travel; means for feeding material into said receptacles at the top of said series; a receiving hopper enclosing the lower sector of said series; and an overflow hop- 5 per enclosing a sector of said series to one side of said receiving hopper, said two hop pers having independent discharges.

In testimony whereof, I afiix my signature.

RANDALL P. AKINS. 

